Method for inhibition of erythrocyte aggregation using anellated tricyclic compounds

ABSTRACT

The present invention is concerned with the use of compounds of the general formula: ##STR1## wherein R 1  is a phenyl radical of the general formula: ##STR2## or R 1  is a 5 or 6 membered heterocycle or when X is a valency bond R 1  is also H, OH, mercapto, amino, alkyl, alkenyl, alkynyl, haloalkyl, alkylthio, formylaminoalkyl, pyridylcarbonylamino, cycloalkyl, or cycloalkenyl, alkoxyalkyl, carboxyalkyl, alkoxycarbonylalkyl or hydroxyalkyl of claim 1 or 2 for the preparation of pharmaceutical compositions with an erythrocyte aggregation inhibition action useful, for example, in states of shock or circulatory disturbance.

The present invention is concerned with the use of compounds ofanellated tricyclic compounds as inhibitors of erythrocyte aggregation.

More particularly, the present invention is concerned with the use ofcompounds of the general formula: ##STR3## wherein R₁ is a phenylradical of the general formula: ##STR4## in which R₂, R₃ and R₄, whichcan be the same or different, are hydrogen atoms, alkanesulphonyloxy,trifluoromethanesulphonyloxy, alkanesulphonylamino,trifluoromethanesulphonylamino, N-alkyl-alkanesulphonylamino,N-alkyl-trifluoromethanesulphonylamino, alkylsulphenylmethyl,alkylsulphinylmethyl or alkylsulphonylmethyl radicals, carbonyl groupssubstituted by hydroxyl, alkoxy, amino, alkylamino or dialkylamino,sulphonyl groups substituted by amino, alkylamino, dialkylamino orcyclic imino, whereby a methylene group in the 4-position can bereplaced by a sulphur or oxygen atom, alkylcarbonylamino,aminocarbonylamino, alkylaminocarbonylamino, alkylthio, alkylsulphinylor alkylsulphonyl radicals, halogen atoms, nitro, cyano, amino orhydroxyl groups or alkyl, alkoxy, alkenyloxy, alkynyloxy, cyanoalkoxy,carboxyalkoxy, alkoxycarbonylalkoxy, dialkylamino, 1-imidazolyl ortrifluoromethyl radicals; or heterocyclic five-membered rings containingup to 4 heteroatoms or heterocyclic six-membered rings containing up to5 heteroatoms, wherein the heteroatoms can be the same or different andare oxygen, sulphur or nitrogen atoms and, if desired, can carry anoxygen atom on one or more nitrogen atoms, and the five- andsix-membered rings can optionally be substituted at least once by alkyl,alkoxy, alkylthio, hydroxyl, nitro, amino, halogen or cyano; or when Xrepresents a valency bond, besides the above-mentioned groups, R₁ canalso be a hydrogen atom, a hydroxyl, mercapto or amino group or analkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, haloalkyl,alkoxyalkyl, carboxyalkyl, alkoxycarbonylalkyl, alkylthio,formylaminoalkyl or pyridylcarbonylamino radical, X is a valency bond oran alkylene or vinylene radical, A is a nitrogen atom or a ##STR5##radical, in which R₅ is a hydrogen atom, a cyano group or an alkyl,alkenyl, cycloalkyl, cycloalkenyl, alkylcarbonyl, alkoxycarbonyl,carboxyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl oraryl radical, B is an oxygen or sulphur atom or an ═NR₆ radical, inwhich R₆ is a hydrogen atom or an alkyl radical, or B can be a ═CR₇ R₈radical, in which R₇ is a hydrogen atom or an alkyl, alkenyl orcycloalkyl radical and R₈ is a hydrogen atom, a cyano group, an alkyl oralkenyl radical, a carbonyl group substituted by hydroxyl, alkyl,alkoxy, amino, alkylamino, dialkylamino or hydrazino or R₇ and R₈together form an alkylidene or cycloalkylidene radical or R₇ and R₈,together with the carbon atom to which they are attached, form aspirocycle; and of the tautomers, optically-active forms and racemicmixtures thereof and the physiologically acceptable salts thereof withinorganic and organic acids for the preparation of pharmaceuticalcompositions with an erythrocyte aggregation-inhibiting action.

The compounds of general formula (I), processes for the preparationthereof and the use thereof as pharmaceuticals are known from EuropeanPat. Specifications Nos. 0,161,632, 0,186,010, 0,189,103, 0,207,483,0,214,592 and 0,216,165. The compounds are described in these EuropeanPatent Specifications as having the following pharmacological actions:increase of the power of the heart, blood pressure lowering, influencingof the thrombocyte aggregation and improvement of the microcirculation.

The compound which are described in the above mentioned applications areprimarily useful however for the treatment of such diseases, in which anincrease of the power of the heart and a blood pressure lowering is wellto the fore, whereby as additional pharmacological effect theimprovement of the flow in the microcirculation is achieved byinhibiting of the thrombocyte aggregation on the one hand and byincreasing the contractility of the heart on the other hand.

Surprisingly, we have now found that compounds of general formula Ipossess a marked action with respect to the inhibition of theerythrocyte aggregation. By this, these compounds are also useful forthe treatment of diseases, in which the erythrocyte aggregation plays animportant part in the pathogenesis, such as, for example, in cases ofperipheral, coronary and cerebral circulation disturbances, varioustypes of ulcer, necrotic processes in tumours, degenerative disorders ofthe retina, nerves and muscles and a wide range of skin disorders.Especially, these compounds can be used for the treatment of arterialocclusion diseases, ischemic disorders, venous insufficiency, ordiabetes mellitus. According to the present invention there can be alsotreated diseases, which are not correlated with a weakening of the heartor an increased blood pressure, but for which a pathologically increasederythrocyte aggregation plays an important part. By this, we haverealized a new promising therapeutical principle, because thesecompounds are the first compounds, which reduce the erythrocyteaggregation at pharmacologically relevant doses, and which arerheologically active.

When, in general formula (II), R₁ is a phenyl ring, then the alkylmoieties of the substituents mentioned in the case of R₂, R₃ and R₄ cancontain up to 5 and preferably up to 4 carbon atoms. Preferred in thissense are, for example, methanesulphonyloxy, ethanesulphonyloxy,n-propanesulphonyloxy, isopropanesulphonyloxy,trifluoromethanesulphonyloxy, methylsulphenylmethyl,ethylsulphenylmethyl, n-propylsulphenylmethyl, methylsulphinylmethyl,ethylsulphinylmethyl, n-propylsulphinylmethyl, methylsulphonylmethyl,ethylsulphonylmethyl, n-propylsulphonylmethyl, methanesulphonylamino,ethanesulphonylamino, n-propanesulphonylamino,trifluoromethanesulphonylamino, N-methyl-methanesulphonylamino,N-ethyl-methanesulphonylamino, N-methyl-ethanesulphonylamino,N-ethylethanesulphonylamino, N-isopropylethanesulphonylamino,N-methyl-n-propanesulphonylamino, N-n-propyl-propane-sulphonylamino,N-merhyl-trifluoromethanesulphonylamino,N-ethyl-trifluoromethanesulphonylamino,N-isopropyl-trifluoromethanesulphonylamino, methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl,methylaminocarbonyl, ethylaminocarbonyl, dimethylaminocarbonyl,di-n-propylaminocarbonyl, N-methyl -ethylaminocarbonyl, trifluoromethyl,methylaminosulphonyl, ethylaminosulphonyl, n-propylaminosulphonyl,n-butylaminosulphonyl, n-pentylaminosulphonyl, dimethylaminosulphonyl,diethylaminosulphonyl, di-n-propylaminosulphonyl,N-methylisopropylaminosulphonyl, acetylamino, propionylamino,methylcarbonylamino, ethylaminocarbonylamino andpropylaminocarbonylamino, methyl, ethyl, propyl, methoxy, ethoxy,propoxy, allyloxy, but-2-enyloxy, but-3-enyloxy, pent-2-enyloxy,propargyloxy, but-2-ynyloxy, but-3-ynyloxy, cyanomethoxy, cyanoethoxy,methoxycarbonylmethoxy, methoxycarbonylethoxy, methylthio, ethylthio,methylsulphinyl, ethylsulphinyl, methylsulphonyl and ethylsulphonylradicals.

Sulphonyl groups substituted by cyclic amino are preferably morpholino,thiomorpholino, pyrrolidino, piperidino and hexamethyleneiminosulphonylgroups.

In particular, R₂ is preferably a hydrogen atom or an alkylsulphonyloxy,trifluoromethylsulphonyloxy, alkylsulphenylmethyl, alkylsulphinylmethyl,alkylsulphonylmethyl, alkylsulphonylamino, N-alkylalkylsulphonylamino,trifluoromethylsulphonylamino or N-alkyl-trifluoromethylsulphonylaminoradical, a carbonyl group substituted by hydroxyl, alkoxy, amino,alkylamino or dialkylamino or a sulphonyl group substituted by amino,dialkylamino or morpholino, in which each of the above-mentioned alkylmoieties can contain 1 or 2 carbon atoms, a nitro or cyano group or analkylaminosulphonyl radical containing up to 4 carbon atoms, analkylcarbonylamino, aminocarbonylamino or N-alkyl-aminocarbonylaminoradical, an alkylthio, alkylsulphinyl or alkylsulphonyl radical, inwhich each of the above-mentioned alkyl moieties can contain 1 or 2carbon atoms, a halogen atom, an amino or hydroxyl group or adialkylamino, alkyl, alkoxy, alkenyloxy or alkynyloxy radical,preferably containing up to 3 carbon atoms, or a cyanomethoxy,methoxycarbonylmethoxy, trifluoromethyl or 1-imidazolyl radical, R₃ ispreferably a hydrogen or halogen atom, an alkyl radical containing up to3 carbon atoms or an alkoxy or dialkylamino radical containing 1 or 2carbon atoms in each alkyl moiety and R₄ is a hydrogen atom or a methoxyradical.

The phenyl radical can contain 1 to 3 of these substituents.

Preferred monosubstituted phenyl compounds are the hydroxy-, C₁ -C₃-alkyl-, C₁ -C₃ -alkoxy-, allyloxy-, propargyloxy-, cyanomethoxy-,methoxycarbonylmethoxy-, halo-, nitro-, cyano-, aminocarbonyl-,methoxycarbonyl-, amino-, C₁ -C₃ -dialkylamino-, C₁ -C₃ -alkylthio -, C₁-C₃ -alkylsulphinyl-, C₁ -C₃ -alkylsulphonyl-, C₁ -C₃ -alkyl-sulphonyloxy- and 1-imidazolyl-phenyls, in which case the substituentcan be in the 2-, 3- or 4-position.

Preferred disubstituted phenyls contain as substituentsalkanesulphonyloxy, trifluoromethylsulphonyloxy, alkylsulphenylmethyl,alkylsulphinylmethyl, alkylsulphonylmethyl, alkylsulphonylamino,N-alkyl-alkylsulphonylamino, trifluoromethylsulphonylamino orN-alkyl-trifluoromethylsulphonylamino radicals, carbonyl groupssubstituted by hydroxy, alkoxy, amino, alkylamino or dialkylamino orsulphonyl groups substituted by amino, dialkylamino or morpholino,alkylaminosulphonyl, alkylcarbonylamino, aminocarbonylamino orN-alkyl-aminocarbonylamino radicals, halogen atoms, hydroxyl, cyano,nitro or amino groups, alkyl, alkoxy, allyloxy, propargyloxy,cyanomethoxy, methoxycarbonylmethoxy, dialkylamino, alkylthio,alkylsulphinyl, alkylsulphonyl or 1-imidazolyl radicals, in which thetwo substituents can be the same or different and can be in the 2,3-,2,4-, 2,5-, 2,6-, 3,4- and 3,5-positions but preferably in the 2,4-,2,5- and 3 4-positions and said alkyl radicals, alone or in combinationwith other radicals, can contain up to 3 carbon atoms.

Preferred trisubstituted phenyls contain hydroxyl groups and methoxyradicals as substituents.

When R₁ signifies a heterocyclic five-membered ring containing up to 4hetero atoms or a heterocyclic six-membered ring containing up to 5heteroatoms, in which the heteroatoms in the said five- and six-memberedrings can be the same or different and are nitrogen, oxygen or sulphuratoms and one or more of the nitrogen atoms can optionally carry anoxygen atom, then preferred in this sense are the pyrrole, furan,thiopb.ene, pyrazole, imidazole, thiazole, isothiazole, oxazole,isoxazole, triazole, tetrazole, thiadiazole, oxadiazole, pyrazine,N,N'-dioxypyrazine, pyrimidine, N,N'-dioxypyrimidine, pyridazine,oxazine, thiazine, triazine, tetrazine, pyridine and N-oxypyridineradicals.

Alkyl, alkoxy and alkylthio substituents in the heterocyclic five- andsix-membered rings can contain up to 6 and preferably up to 4 carbonatoms, the methyl, ethyl, methoxy, ethoxy, methylthio and ethylthioradicals being preferred. Halogen is to be understood to be a fluorine,chlorine or bromine atom, chlorine being preferred.

If X is a valency bond and R₁ is an alkyl, alkenyl or alkynyl radical,then straight-chained and branched chains containing up to 8 carbonatoms are thereby to be understood. Preferred in this sense are methyl,ethyl, propyl, butyl, pentyl, hexyl, vinyl, propenyl and propynylradicals.

If X is a valency bond and R₁ is a cycloalkyl or cycloalkenyl radical,then there are thereby to be understood rings containing 3 to 6 members.Preferred in this sense are the cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cyclopentenyl and cyclohexenyl radicals.

If X is a valency bond and R₁ an alkoxyalkyl, carboxyalkyl,alkoxycarbonylalkyl or hydroxyalkyl radical, then the alkyl and alkoxymoieties can contain up to 6 carbon atoms. Preferred in this sense arethe ethoxymethyl, methoxyethyl, ethoxyethyl, carboxymethyl,carboxypropyl, carboxybutyl, methoxycarbonylmethyl,methoxycarbonylethyl, methoxycarbonylpropyl, ethoxycarbonylmethyl,ethoxycarbonylethyl, ethoxycarbonylpropyl, propoxycarbonylethyl,hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxybutyl radicals.

X is preferably a valency bond or a methylene, ethylene or vinyleneradical.

If A is ##STR6## radical and R₅ is an alkyl-carbonyl, alkoxycarbonyl,aminocarbonyl, alkylaminocarbonyl or dialkylaminocarbonyl radical, thenthe alkyl and alkoxy moieties can contain up to 7 and preferably up to 5carbon atoms, the acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl,aminocarbonyl, methylaminocarbonyl and dimethylaminocarbonyl radicalsthereby being preferred.

If B signifies an ═NR₆ radical and R₆ an alkyl radical, then methyl,ethyl, propyl, isopropyl, butyl, 2-butyl and 1,1-dimethylethyl radicalsare preferred.

If B is a ═CR₇ R₈ radical and R₇ and/or R₈ is an alkyl, cycloalkyl,alkenyl radical or a carbonyl group substituted by alkyl, alkoxy,alkylamino or dialkylamino, then each of the alkyl and alkenyl moietiescan be straight-chained or branched and contains 1 to 6 or 2 to 6 carbonatoms, respectively, and the cycloalkyl moiety contains 3 to 7 carbonatoms.

Preferred in this sense for R₇ is a hydrogen atom or a methyl, ethyl,isopropyl, 3-pentyl, cyclopentyl or cyclohexyl radical. R₈ is preferablya hydrogen atom, a cyano or carboxyl group or a methyl, ethyl,isopropyl, 3-pentyl, acetyl, propynyl, methoxycarbonyl, ethoxycarbonyl,aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl orhydrazinocarbonyl radical.

If R₇ and R₈, together with the carbon atom to which they are attached,form a cycloalkyl ring, then this is preferably a spirocyclopropyl,spirocyclobutyl, spirocyclopentyl or spirocyclohexyl ring. If R₇ and R₈together form an alkylidene or cycloalkylidene radical, then theisopropylidene and cyclohexylidene rings are preferred.

Especially preferred are compounds of general formula (I), wherein R₁ isa phenyl radical of general formula (II) in which R₂ is a hydrogen orchlorine atom, a cyano, nitro or amino group or a methanesulphonyloxy,trifluoromethanesulphonyloxy, methanesulphonylamino,trifluoromethanesulphonylamino, methanesulphonylmethylamino,trifluoromethanesulphonylmethylamino, methylsulphinylmethyl,methylsulphonylmethyl, aminocarbonyl, aminosulphonyl,methylaminosulphonyl, dimethylaminosulphonyl, acetylamino, methylthio,methylsulphinyl, methylsulphonyl, hydroxyl, allyloxy, methyl, methoxy,propargyloxy, cyanomethoxy, methoxycarbonylmethoxy, dimethyylamino,trifluoromethyl or 1-imidazolyl radical, R₃ is a hydrogen or chlorineatom, a hydroxyl group or a methyl, methoxy or dimethylamino radical andR₄ is a hydrogen atom or a methoxy radical or R₁ is a pyrrole, furan,thiophene, pyrazole, imidazole, isothiazole, thiazole, oxazole,triazole, tetrazole, thiadiazole, isoxazole, oxadiazole, pyridine,N-oxypyridine, pyrazine, pyrimidine, N,N'-dioxypyrimidine, pyridazine,oxazine, thiazine, triazine or tetrazine radical or a methyl-, ethyl-,methoxy-, ethoxy-, methylthio-, ethylthio- or chloro-substitutedderivative thereof or, when X is a valency bond, besides theabove-mentioned groups, R₁ can also be a hydrogen atom, a hydroxyl,mercapto or amino group or a methyl, ethyl, propyl, butyl, pentyl,hexyl, propenyl, cyclopentenyl, cyclohexyl, trifluoromethyl ormethylthio radical, X is a valency bond or an ethylene or vinyleneradical, A is a nitrogen atom or a ##STR7## radical, B is an oxygen orsulphur atom or an═NR₆ radical, in which R₆ is a methyl, ethyl or propylradical or B is a═CR₇ R₈ radical, in which R₇ is a hydrogen atom or amethyl radical and R₈ is a methyl, ethyl or isopropyl radical or R₇ andR₈, together with the carbon atom to which they are attached, form aspirocyclopentyl ring.

For the preparation of pharmaceutical compositions, the compounds ofgeneral formula (I) are mixed in known manner with appropriatepharmaceutical carrier materials, aroma, flavouring and colouringmaterials and formed, for example, into tablets or dragees or, with theaddition of appropriate adjuvants, are suspended or dissolved in wateror in an oil, for example olive oil.

The compounds of general formula (I) and the salts thereof canbeadministered enterally or parenterally in liquid or solid form, Asinjection medium, it is preferred to use water which contains theadditives usual in the case of injection solutions, such as stabilisingagents, solubilising agents and buffers.

Such additives include, for example, tartrate and citrate buffers,ethanol, complex formers (such as ethylenediamine-tetraacetic acid andthe non-toxic salts thereof) and high molecular weight polymers (such asliquid polyethylene oxide) for viscosity regulation. Solid carriermaterials include, for example, starch, lactose, mannitol, methylcellulose, talc, highly dispersed silicic acids, high molecular weightfatty acids (such as stearic acid), gelatine, agar-agar, calciumphosphate, magnesium stearate, animal and vegetable fats and solid highmolecular weight polymers (such as polyethylene glycol). Compositionssuitable for oral administration can, if desired, contain flavouring andsweetening agents.

The compounds are usually administered in amounts of from 10 to 2000 mg.per day, referred to a body weight of 75 kg. It is preferred toadminister 1 or 2 tablets which have an active material content of from5 to 500 mg. 2 or 4 times a day. The tablets can also be retarded, inwhich case only 1 or 2 tablets with an active material content of from20 to 1000 mg. have to be administered once per day. The active materialcan also be administered by injection 1 to 8 times a day or bycontinuous infusion, in which case 10 to 1000 mg. per day normallysuffice.

The determination of the erythrocyte aggregation takes place with amini-erythrocyte aggregometer of the firm Myrenne, Rotgen (seeKiesewetter et al., Biomed. Tecknik, 27, 209-213/1982). As a measure,this apparatus gives a dimensionless index which increases withincreasing aggregation tendency.

The investigations were carried out with human blood from healthydonors. The blood was adjusted to a haematocrit of 45% and incubatedwith a control solution or with a solution of a test substance. Theerythrocyte aggregation was then measured. Each compound wasinvestigated in a concentration of 10⁻⁵ molar. Per compound there werecarried out two investigations with the blood from two donors. There wascalculated the difference of the aggregation indices between the initialvalue of the control solution and the values with the solutions of thetest compounds (ΔE).

In the following Table, there are set out the findings obtained for theerythrocyte aggregation (ΔE). The lower is the given value, the moreeffective is the test compound. On the other hand, venoruton, a mixtureof various 0-(β-hydroxyethyl)-rutosides, at a comparable concentrationof 1.7×10⁻⁵ M, only brings about a change of the erythrocyte aggregationindex of -0.4. Even at a concentration of 1.7×10⁻³ M, the change onlyamounts to -3.9±0.9. Venoruton is said to inhibit the tendency towardserythrocyte aggregation (see Schmid-Schonbeim et al., VASA, 4,263-270/1975).

In comparison with the prior art, the compounds used according to thepresent invention clearly inhibit the erythrocyte aggregation morestrongly.

It will be understood that the specification and examples areillustrative but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

    ______________________________________                                                                 m.p.      ΔE                                   No.   compound           (°C.)                                                                            [10.sup.-5 M]                              ______________________________________                                         1    7,7-dimethyl-2-(4-pyridyl)-                                                                      215       -8                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one ×                                             4 H.sub.2 O                                                              2    7,7-dimethyl-2-(2-pyridyl)-                                                                      182-187   -4                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one ×                                             0.3 H.sub.2 O                                                            3    7,7-dimethyl-2-(3-pyridyl)-                                                                      331-335   -4                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one ×                                             4 H.sub.2 O                                                              4    7,7-dimethyl-2-(4-(2-                                                                            311-313   -9                                               methylpyridyl)-6,7-dihydro-                                                   3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one × 0.6 H.sub.2 O                                     5    7,7-dimethyl-2-(4-(2-                                                                            >360      -1                                               hydroxypyridyl))-6,7-                                                         dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one ×                                             2 H.sub.2 O                                                              6    7,7-dimethyl-2-(4-(2-chloro-                                                                     341-344   -11                                              pyridyl))-6,7-dihydro-                                                        3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                           7    7,7-dimethyl-2-(2-(3-                                                                            203-207   -8                                               pyridyl)-ethenyl)-6,7-                                                        dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one ×                                             0.6 H.sub.2 O                                                            8    7,7-dimethyl-2-(2-(4-                                                                            150-154   -1                                               pyridyl)-ethyl)-6,7-                                                          dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                                9    2'-(4-pyridyl)-spiro[cyclo-                                                                      >365      -9                                               pentan-1,7',6,7'-dihydro-                                                     3'H,5'H-pyrrolo[2',3' -f]-                                                    benzimidazol 6'-one × 0.3                                         10    7,7-dimethyl-2-(3-(6-methyl-                                                                     >360      -4                                               pyridyl))-6,7-dihydro-3H,5H-                                                  pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   11    7,7-dimethyl-2-(3-(2-                                                                            296-298   -9                                               methoxy-6-methyl)-pyridyl)-                                                   6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               12    7,7-dimethyl-2-(4-N-oxy-                                                                         260-262   -2                                               pyridyl)-6,7-dihydro-3H,5H-                                                   pyrrolo[2,3-f]benzimidazol-                                                   6-one × 3 H.sub.2 O                                               13    7-ethyl-2-(4-pyridyl)-6,7-                                                                       270-272   -2                                               dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               14    7-ethyl-2-(3-pyridyl)-6,7-                                                                       >300      -2                                               dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               15    7-(2-propyl)-2-(4-pyridyl)-                                                                      215-220   -2                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               16    7-cyclopentyl-2-(4-pyridyl)-                                                                     200-204   -2                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               17    7,7-diethyl-2-(4-pyridyl)-                                                                       216-219   -5                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               18    7-ethoxycarbonyl-7-methyl-                                                                       288-290   -2                                               2-(4-pyridyl)-6,7-dihydro-                                                    3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one × HCl                                              19    7-(2-methylpropyl)-2-(4-                                                                         200-202   -1                                               pyridyl)-6,7-dihydro-3H,5H-                                                   pyrrolo[2,3-f]benzimidazol-                                                   6-one × 1.5 H.sub.2 O                                             20    7,7-dimethyl-2-(4-(3-                                                                            >300      -8                                               hydroxypyridyl)-6,7-                                                          dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               21    7,7-dimethyl-2-(2-(5-n-                                                                          176-178   -7                                               butylpyridyl))-6,7-dihydro-                                                   3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          22    7,7-dimethyl-2-(2-furanyl)-                                                                      311-3l6   -5                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               23    7,7-dimethyl-2-(2-thienyl)-                                                                      322-336   - 8                                              6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               24    7,7-dimethyl-2-(2-pyrazinyl)-                                                                    >300      -2                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               25    7,7-dimethyl-2-(4-thiazolyl)-                                                                    280       -3                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               26    7,7-dimethyl-2-(2-methyl-                                                                        >350      -4                                               pyrimidin-5-yl)-6,7-dihydro-                                                  3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          27    7,7-dimethyl-2-(l,2,4-1H-                                                                        >350      -3                                               triazol-3-yl)-6,7-dihydro-                                                    3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          28    7,7-dimethyl-2-(2-methyl-                                                                        315-3l8   -2                                               oxazol-4-yl)-6,7-dihydro-                                                     3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          29    7-methyl-7-ethoxycarbonyl-                                                                       213-214   -3                                               2-(2-pyrazinyl)-6,7-dihydro-                                                  3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          30    7,7-dimethyl-2-(2-thienyl-                                                                       233-235   -3                                               methyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   31    7,7-dimethyl-2-(1,2,3-thia-                                                                      >300      -3                                               diazol-4-yl)-6,7-dihydro-                                                     3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          32    7,7-dimethyl-2-(1,2,3-thia-                                                                      286-290   -9                                               diazol-5-yl)-6,7-dihydro-                                                     3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          33    7,7-dimethyl-2-(2-methylthio-                                                                    311       -3                                               1,3,4-oxadiazol-5-yl)-6,7-                                                    dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               34    7,7-dimethyl-2-(4-methoxy-                                                                       >300      -1                                               carbonyl-1,2,3-1H-triazol-5-                                                  yl)-6,7-dihydro-3H,5H-                                                        pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   35    2'-(4-pyridazinyl)-spiro-                                                                        365-367   -8                                               [cyclopentane-1,7'-6',7'-                                                     dihydro-3'H,5'H-pyrrolo-                                                      [2',3'-f]benzimidazol]-6'-                                                    one                                                                     36    7-ethyl-2-(4-pyridazinyl)-                                                                       >300      -5                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               37    2' -(2-furanyl)-spiro[cyclo-                                                                     >300      -9                                               pentane-l,7'-6',7'-dihydro-                                                   3'H,5'H-pyrrolo[2',3'-f]-                                                     benzimidazol]-6'-one                                                    38    7,7-dimethyl-2-(4-nitro-                                                                         >300      -5                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   39    7,7-dimethyl-2-(4-amino-                                                                         225-230   -6                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   40    7,7-dimethyl-2-(2-hydroxy-                                                                       371-373   -9                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   41    7,7-dimethyl-2-(3,4-dichloro-                                                                    >300      -10                                              phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   42    7,7-dimethyl-2-(2-phenyl-                                                                        320-325   -10                                              vinyl)-6,7-dihydro-3H,5H-                                                     pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   43    7,7-dimethyl-2-(2-methoxy-4-                                                                     217-220   -10                                              methylsulphinylphenyl)-6,7-                                                   dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               44    7,7-dimethyl-2-(4-trifluoro-                                                                     >300      -7                                               methylphenyl)-6,7-dihydro-                                                    3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          45    2'-phenyl-spiro[cyclo-                                                                           353-355   -10                                              pentane-1,7'-6',7'-dihydro-                                                   3'H,5'H-pyrrolo[2',3'-f]-                                                     benzimidazol]-6'-one                                                    46    2'-(2-methoxy-4-hydroxy-                                                                         335-340   -5                                               phenyl)-spiro[cyclopentane-                                                   1.7'-6',7'-dihydro-3'H,5'H-                                                   pyrrolo[2',3'-f]benzimidazol]-                                                6'-one                                                                  47    2'-(2-methoxy-4-methyl-                                                                          270-272   -5                                               sulphonylphenyl)-spiro-                                                       [cyclopentane-1,7'-6',7'-                                                     dihydro-3'H,5'H-pyrrolo-                                                      [2',3' -f]benzimidazol]-                                                      6'-one                                                                  48    7-isopropyl-2-(4-methoxy-                                                                        326-328   -8                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   49    7,7-dimethyl-2-phenylmethyl-                                                                     328-330   -1                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               50    7,7-dimethyl-2-(2-methoxy-                                                                       300-303   -10                                              phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   51    7,7-dimethyl-2-(4-methoxy-                                                                       341-343   -7                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   52    7,7-dimethyl-2-(4-chloro-                                                                        360-363   -3                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   53    7,7-dimethyl-2-(2-methoxy-5-                                                                     236-238   -2                                               methylsulphonylphenyl)-6,7-                                                   dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               54    7,7-dimethyl-2-(4-methyl-                                                                        >300      -10                                              phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   55    7,7-diethyl-2-(4-methoxy-                                                                        217-219   -4                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   56    2'-(4-methoxyphenyl)-spiro-                                                                      354-355   -10                                              [cyclopentane-1,7'-6',7'-                                                     dihydro-3'H,5'H-pyrrolo-                                                      [2',3'-f]benzimidazol]-6'-                                                    one                                                                     57    7-methyl-2-(2,4-dimethoxy-                                                                       294-297   -2                                               phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   58    7,7-dimethyl-2-(4-hydroxy-                                                                       240       -12                                              phenyl)-6,7-dihydro-3H,5H-                                                    pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   59    7,7-dimethyl-2-phenyl-6,7-                                                                       195-220   -8                                               dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               60    7,7-dimethyl-2-(2,4-                                                                             294-297   -10                                              dimethoxyphenyl)-6,7-                                                         dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               61    7,7-dimethyl-2-(3,4-                                                                             314-317   -14                                              dimethoxyphenyl)-6,7-                                                         dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               62    7,7-dimethyl-2-(2-methoxy-4-                                                                     299-30l   -13                                              chlorophenyl)-6,7-dihydro-                                                    3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          63    7,7-dimethyl-2-[4-(1H-                                                                           300       -11                                              imidazol-l-yl)-phenyl]-6,7-                                                   dihydro-3H,5H-pyrrolo[2,3-f]-                                                 benzimidazol-6-one                                                      64    7,7-dimethyl-2-(4-dimethyl-                                                                      262-270   -8                                               aminophenyl)-6,7-dihydro-                                                     3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          65    7,7-dimethyl-2-(2-methoxy-4-                                                                     233-235   -8                                               methylsulphonylphenyl)-6,7-                                                   dihydro-3H,5H-pyrrolo[2,3-f]-                                                 benzimidazol-6-one                                                      66    7-ethoxycarbonyl-7-methyl-                                                                       178-182   -3                                               2-phenyl-6,7-dihydro-3H,5H-                                                   pyrrolo[2,3-f]benzimidazol-                                                   6-one                                                                   67    7,7-dimethyl-2-(2-methoxy-4-                                                                     235-237   -10                                              methylsulphonylphenyl)-6,7-                                                   dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               68    6-phenyl-1-methyl-1,2,3,5-                                                                       >300      -1                                               tetrahydrobenzo[1,2-d:                                                        4,5-d']diimidazol-2-one                                                 69    6-(4-dimethylaminophenyl)-                                                                       238-24l   -5                                               1-methyl-1,2,3,5-tetrahydro-                                                  benzo[1,2-d:4,5-d']diimidazol-                                                2-one                                                                   70    6-(4-(l-imidazolyl)-phenyl)-                                                                     260       -5                                               1-methyl-1,2,3,5-tetrahydro-                                                                     (decomp.)                                                  benzo[1,2-d:4,5-d']-                                                          diimidazol-2-one                                                        71    6-(4-diethylamino-2-methoxy-                                                                     >300      -9                                               phenyl)-1-methyl-1,2,3,5-                                                     tetrahydrobenzo[1,2-d:                                                        4,5-d']diimidazol-2-one                                                 72    6-(4-pyridyl)-1-ethyl-                                                                           237-239   -3                                               1,2,3,5-tetrahydrobenzo-                                                      [1,2-d:4,5-d']diimidazol-2-                                                   one                                                                     73    6-(4-pyridyl)-1-(1-propyl)-                                                                      235-237   -5                                               1,2,3,5-tetrahydrobenzo-                                                      [1,2-d:4,5-d']diimidazol-2-                                                   one                                                                     74    6-(4-pyridazinyl)-1-methyl-                                                                      >300      - 2                                              [1,2,3,5-tetrahydrobenzo-                                                     [1,2-d:4,5-d']diimidazol-2-                                                   one                                                                     75    6-(4-pyridazinyl-1-ethyl-                                                                        >300      -4                                               1,2,3,5-tetrahydrobenzo-                                                      [1,2-d:4,5-d']diimidazol-2-                                                   one                                                                     76    6-(3-thienyl)-2,3-dihydro-                                                                       295-300   -2                                               5H-imidazol[4,5-f]benzoxazol                                                  2-one                                                                   77    6-(4-pyridyl)-2,3-dihydro-                                                                       >300                                                       5H-imidazo[4,5-f]benz-                                                        thiazol-2-one                                                           78    6-pyrazinyl-2,3-dihydro-5H-                                                                      335       -2                                               imidazo[4,5-f]benzoxazol-2-                                                   one                                                                     79    6-(2-methylthiophenyl)-2,3-                                                                      208-211   -2                                               dihydro-5H-imidazo[4,5-f]-                                                    benzoxazol-2-one                                                        80    6-(2-methoxyphenyl)-2,3-                                                                         319-321   -5                                               dihydro-5H-imidazo[4,5-f]-                                                    benzoxazol-2-one                                                        81    6-phenyl-2,3-dihydro-5H-                                                                         298-300   -4                                               imidazo[4,5-f]benzoxazol-2-                                                   one                                                                     82    6-(2-methyl-4-pyridyl)-2,3-                                                                      >300      -3                                               dihydro-5H-imidazo[4,5-f]-                                                    benzoxazol-2-one                                                        83    6-(1-propyl)-2,3-dihydro-5H-                                                                     177-180   -2                                               imidazo[4,5-f]benzoxazol-2-                                                   one                                                                     84    3,3-dimethyl-6-(4-pyridyl)-                                                                      >300      -3                                               benzo[1,2-b:5,4-b']dipyrrol-                                                  2-(1H,3H,7H)-one                                                        85    3,3-dimethyl-6-(3-pyridyl)-                                                                      305       -6                                               benzo[1,2-b:5,4-b']dipyrrol-                                                  2-1H,3H,7H)-one × CH.sub.3 OH                                     86    3,3-dimethyl-6-[4-(1H-                                                                           >340      -6                                               imidazol-1-yl-phenyl]-benzo-                                                  [1,2-b:5,4-b']dipyrrol-2-                                                     (1H,3H,7H)-one                                                          87    3-methyl-6-(3-pyridyl)-benzo-                                                                    330-331   -2                                               [1,2-b:5,4-b']dipyrrol-2-                                                     (1H,3H,7H)-one                                                          88    3-methyl-6-(3-pyridyl)-benzo-                                                                    270-273   -10                                              [1,2-b:5,4-b']dipyrrol-2-                                                     (1H,3H,7H)-one                                                                3,3-dimethyl-6-(4-methyl-                                                                        278-281   -4                                               phenyl)-benzo[1,2-b:5,4-b']-                                                  dipyrrol-2-(1H,3H,7H)-one                                               90    7,7-dimethyl-2-cyclohexyl-                                                                       315-318   -4                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               91    2'-propyl-spiro[cyclopentan-                                                                     332-335   -6                                               1,7'-6',7'-dihydro-3'H,5'H-                                                   pyrrolo[2',3'-f]benz-                                                         imidazol]-6'-one                                                        92    2-(1-propenyl)-7,7-dimethyl-                                                                     252-254   -7                                               6,7-dihydro-3H,5H-pyrrolo-                                                    [2,3-f]benzimidazol-6-one                                               93    2-n-hexyl-7,7-dimethyl-6,7-                                                                      233-234   -8                                               dihydro-3H,5H-pyrrolo-                                                        [2,3-f]benzimidazol-6-one                                               94    7,7-dimethyl-2-(1-cyclo-                                                                         233-235   -6                                               penten-1-yl)-6,7-dihydro-                                                     3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          95    2-(4-pyridylcarbonylamino)-                                                                      >300      -7                                               7,7-dimethyl-6,7-dihydro-                                                     3H,5H-pyrrolo[2,3-f]benz-                                                     imidazol-6-one                                                          96    2'-(4-Ethoxyphenyl)spiro                                                                         >300      -9                                               [cyclo-pentan-1,7'-6',7'-                                                     dihydro-3'H,5'H-pyrrolo                                                       [2',3'-f]-benzimidazol-6'-on,                                                 prepared according to                                                         EP 186 010                                                              ______________________________________                                    

What is claimed:
 1. A method for the inhibition of erythrocyteaggregation which comprises treating patients with conditions havingneed of such inhibition with an effective amount of a compound of theformula: ##STR8## wherein R₁ is a phenyl of the formula: ##STR9##wherein R₂, R₃, R₄, which can be the same or different, are hydrogen, C₁-C₅ alkanesulphonyloxy, trifluormethanesulphonyloxy, C₁ -C₅alkanesulphonylamino, trifluorometanesulphonylamino, C₁ -C₅ N-alkyl-C₁-C₅ -alkanesulphonylamino, C₁ -C₅N-alkyl-trifluoromethanesulphonylamino, C₁ -C₅ alky.lsulphenylmethyl, C₁-C₅ alkylsulphinylmethyl, C₁ -C₅ alkylsulphonylmethyl or,carbonyl groupssubstituted by hydroxyl C₁ -C₅ -alkoxy amino C₁ -C₅ -alkylamino, di-C₁-C₅ -alkylamino, or sulphonyl groups substituted by amino, C₁ -C₅-alkylamino, di-C₁ -C₅ -alkylamino or cyclic imino, wherein a methylenegroup in the 4-position of the cyclic imino can be replaced by a sulphuror oxygen atom, or C₁ -C₅ alkyl-carbonylamino, amino-carbonylamino, C₁-C₅ -alkyl-aminocarbonylamino, C₁ -C₅ -alkylthio, C₁ -C₅-alkylsulphinyl, C₁ -C₅ -alkylsulphonyl, or halogen, nitro, cyano,amino, hydroxyl, C₁ -C₅ -alkoxy, C₁ -C₅ -alkyl, C₂ -C₅ -alkenyloxy, C₂-C₅ -alkynyloxy, cyano-C₁ -C₅ alkoxy, carboxy-C₁ -C₅ -alkoxy, C₁ -C₅-alkoxycarbonyl-C₁ -C₅ alkoxy, di-C₁ -C₅ -alkylamino, 1-imidazolyl,trifluoromethyl; or R₁ is a heterocyclic five-membered ring containingup to 4 heteroatoms, or heterocyclic six-membered rings containing up to5 heteroatoms, wherein the heteroatoms in the 5- or 6-membered ring canbe the same or different and are oxygen, sulphur or nitrogen atoms and,can carry an oxygen atom on one or more nitrogen, atoms, and the five-and six-membered rings can be unsubstituted or substituted at least onceby C₁ -C₆ -alkyl, C₁ -C₆ -alkoxy, C₁ -C₆ -alkylthio, hydroxyl, nitro,amino, halogen or cyano; or when X represents a valency bond, besidesthe above-mentioned groups, R₁ can also be hydrogen, hydroxyl, mercaptoamino or C₁ -C₈ -alkyl, C₃ -C₆ -cycloalkenyl, C₂ -C₈ -alkenyl, C₃ -C₆-cyclo-alkenyl, C₂ -C₈ alkynyl, C₁ -C₈ -haloalkyl, C₁ -C₈ hydroxyalkyl,C₁ -C₈ alkoxyalkyl, C₁ -C⁸ carboxyalkyl, C₁ -C₈ alkoxycarbonyl C₁ -C₈-alkyl, C₁ -C₈ -alkylthio, formylamino-C₁ -C₈ -alkyl orpyridylcarbonylamino, X is a valency bond or an C₁ -C₈ alkylene orvinylene, A is nitrogen or--CR₅ wherein R₅ is hydrogen, cyano, C₁ -C₇-alkyl, C₂ -C₇ alkenyl, C₃ -C₇ cycloalkyl, C₃ -C₇ -cycloalkenyl, C₁ -C₇-alkylcarbonyl, C₁ -C₇ -alkoxycarbonyl, carboxyl, aminocarbonyl, C₁ -C₇-alkylaminocarbonyl, di-C₁ -C₇ -alkylaminocarbonyl or aryl, B is oxygen,sulphur or═NR₆ wherein R₆ is hydrogen or C₂ -C₆ -alkyl, or B is═CR₇ R₈,wherein R₇ is hydrogen, C₁ -C₆ -alkyl, C₂ -C₆ -alkenyl or C₃ -C₇-cycloalkyl and R₈ is hydrogen, cyano, C₁ -C₆ -alkyl, C₂ -C₆ -alkenyl ora carbonyl substituted by hydroxyl, C₁ -C₆ -alkyl C₁ -C₆ -alkoxy amino,C₁ -C₆ -alkylamino, di-C₁ -C₆ -alkylamino or hydrazino, or R₇ and R₈together form an C₁ -C₆ -alkylidene or C₃ -C₇ -cycloalkyliden, or R₇ andR₈, together with the carbon atom to which they are attached, form a C₃-C₇ -spirocycle; and the tautomers, optically-active forms and racemicmixtures thereof and the physiologically acceptable salts thereof withinorganic and organic acids in a pharmaceutically acceptable carrier. 2.The method of claim 1, comprising treating said conditions with apharmaceutically effective amount of a compound of Formula I wherein R₁is a phenyl radical of formula (II) wherein R₂ is hydrogen, halogen,cyano, nitro, amino or a methanesulphonyloxy,trifluoromethanesulphonyloxy, methanesulphonylamino,trifluoromethanesulphonylamino, methanesulphonylmethylamino,trifluoromethanesulphonylmethylamino, methylsulphinylmethyl,methylsulphonylmethyl, aminocarbonyl, aminosulphonyl,methylaminosulphonyl, dimethylaminosulphonyl, acetylamino, methylthio,methylsulphinyl, methylsulphonyl, hydroxyl, allyloxy, methyl, methoxy,propargyloxy, cyanomethoxy, methoxycarbonylmethoxy, dimethylamino,trifluoromethyl or 1-imidazolyl,R₃ is hydrogen, chlorine, hydroxyl,methyl, methoxy or dimethylamino, and R₄ is hydrogen or methoxy; or R₁is pyrrolyl, furanyl, thiophenyl, pyrazolyl, imidazolyl, isothiazolyl,thiazolyl, oxazolyl, triazolyl, tetrazolyl, thiadiazolyl, isoxazolyl,oxadiazolyl, pyridinyl, N-oxypyridinyl, pyrazinyl, pyrimidinyl,N,N'-dioxypyrimidinyl, pyridazinyl, oxazinyl, thiazinyl, triazinyl,tetrazinyl or a methyl-, ethyl-, methoxy-, ethoxy-, methylthio-,ethylthio-, or chloro-substituted derivative thereof or, when X is avalency bond, besides the above-mentioned groups R₁ is hydrogen,hydroxyl, mercapto, amino, methyl, ethyl, propyl, butyl, pentyl, hexyl,vinyl propenyl, propynyl, cyclopentenyl, cyclohexyl, trifluoromethyl ormethylthio, X is a valency bond, ethylene or vinylene, A is nitrogenor--CH, B is oxygen, sulphur or═NR₆, wherein R₆ is methyl, ethyl orpropyl, or B is═CR₇ R₈, wherein R₇ is hydrogen or methyl and R₈ ismethyl, ethyl or isopropyl, or R₇ or R₈, together with the carbon atomto which they are attached, form a spirocyclopentyl ring.
 3. The methodof claim 1 or claim 2 comprising treating said conditions with apharmaceutically effective amount of a compound of Formula I whereinwhen R₁ is Formula II then R₂, R₃ and R₄ are methanesulphonyloxy,ethanesulphonyloxy, n-propanesulphonyloxy, isopropanesulphonyloxy,trifluoromethanesulphonyloxy, methylsulphenylmethyl,ethylsulphenylmethyl, n-propylsulphenylmethyl, methylsulphinylmethyl,ethylsulphinylmethyl, n-propylsulphinylmethyl, methylsulphonylmethyl,ethylsulphonylmethyl, n-propylsulphonylmethyl, methanesulphonylamino,ethanesulphonylamino, n-propanesulphonylamino,trifluoromethanesulphonylamino, N-methyl-methanesulphonylamino,N-ethylmethanesulphonylamino, N-methyl-ethanesulphonylamino,N-ethylethanesulphonylamino, N-isopropylethanesulphonylamino,N-methyl-n-propanesulphonylamino, N-n-propyl-propanesul-phonylamino,N-methyltrifluoromethanesulphonylamino,N-ethyltrifluoromethanesulphonylamino,N-isopropyl-trifluoromethanesulphonylamino, methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl,methylaminocarbonyl, ethylaminocarbonyl, dimethylaminocarbonyl,di-n-propylaminocarbonyl, N-methyl-ethylaminocarbonyl, trifluoromethyl,methylaminosulphonyl, ethylaminosulphonyl, n-propylaminosulphonyl,n-butyl aminosulphonyl, n-pentylaminosulphonyl, dimethylaminosulphonyl,diethylaminosulphonyl, di-n-propylaminosulphonyl,N-methyl-isopropylaminosulphonyl, acetylamino, propionylamino,methylcarbonylamino, ethylaminocarbonylamino andpropylaminocarbonylamino, methyl, ethyl, propyl, methoxy, ethoxy,propoxy, allyloxy, but-2-enyloxy, but-3-enyloxy, pent-2enyloxy,propargyloxy, but-2-ynyloxy, but-3-ynyloxy, cyanomethoxy, cyanoethoxy,methoxycarbonylmethoxy, methoxycarbonylethoxy, methylthio, ethylthio,methylsulphinyl, ethylsulphinyl, methylsulphonyl and ethylsulphonyl;andwherein the sulphonyl groups substituted by cyclic amino are selectedfrom the group consisting of morpholino, thiomorpholino, pyrrolidino,piperidino and hexamethyleneiminosulphonyl.
 4. The method of claim 1 orclaim 2 comprising treating said conditions with a compound of formula Iwherein R₁ is a phenyl of formula II and wherein the monosubstitutedphenyl compounds are hydroxy-, C₁ -C₃ -alkyl-, C₁ -C₃ -alkoxy-,allyloxy-, propargyloxy-, cyanomethoxy-, methoxycarbonylmethoxy-, halo-,nitro-, cyano-, aminocarbonyl-, methoxycarbonyl-, amino-, C₁ -C₃-dialkylamino-, C₁ -C₃ -alkylthio-, C₁ -C₃ -alkyl-sulphinyl- , C₁ -C₃-alkylsulphonyl-, C₁ -C₃ -alkylsulphonyloxy- and 1-imidazolyl-phenyls,wherein the substitutent is in the 2-, 3- or 4-position,anddisubstituted phenyls are C₁ -C₃ alkanesulphonyloxy,trifluoromethylsulphonyloxy, C₁ -C₃ alkylsulphenylmethyl, C₁ -C₃alkylsulphinylmethyl, C₁ -C₃ alkylsulphonylmethyl, C₁ -C₃alkylsulphonylamino, C₁ -C₃ N-alkyl-alkylsulphonylamino,trifluoromethylsulphonylamino, N-alkyl-trifluoromethylsulphonylamino, orcarbonyl groups substituted by hydroxy, alkoxy, amino, C₁ -C₃ alkylaminoor C₁ -C₃ dialkylamino or sulphonyl substituted by amino, C₁ -C₃dialkylamino or morpholino, C₁ -C₃ alkylaminosulphonyl, C₁ -C₃alkylcarbonylamino carbonylamino, aminocarbonylamino or N-alkyl-aminocarbonylamino, halogen, hydroxyl, cyano, nitro or amino C₁ -C₃alkyl, C₁ -C₃ alkoxy allyloxy, propargyloxy, cyanomethoxy,methoxycarbonylmethoxy, C₁ --C₃ dialkylamino, C₁ -C₃ alkylthio, C₁ -C₃alkylsulphonyl, C₁ -C₃ alkylsulphonyl or 1-imidazolyl radicals, in whichthe two substituents can be the same or different and can be in the2,3-, 2,4- 2,5-, 2,6-, 3,4- and 3,5- positions, and trisubstitutedphenyls comprise hydroxyl and methoxy substituents.
 5. The method ofclaim 4 wherein the disubstituted phenyl is in the 2,4-, 2,5- or3,4-position.
 6. The method of claim 1 or claim 2 comprising treatingsaid conditions with a compound of Formula I wherein R₁ is pyrrole,furan, thiophene, pyrazole, imidazole, thiazole, isothiazole, oxazole,isoxazole, triazole, tetrazole, thiadiazole, oxadiazole, pyrazine,N,N'-dioxypyrazine, pyrimidine, N,N'-dioxypyrimidine, pyridazine,oxazine, thiazine, triazine, tetrazine, pyridine or N-oxypyridine, andwherein the above ring is unsubstituted or wherein the substituentsthereon are methyl, ethyl, methoxy, ethoxy, methylthio and ethylthio. 7.The method of claim 1 or claim 2 comprising treating said conditionswith a compound of Formula I wherein X is a valency bond or methylene,ethylene or vinylene, and when X is a valency bond,R₁, is methyl, ethyl,propyl, butyl, pentyl, hexyl, vinyl, propenyl or propynyl, or R₁ iscyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentenyl orcyclohexenyl, or R₁ is ethoxymethyl, methoxyethyl, ethoxyethyl,carboxymethyl, carboxypropyl, carboxybutyl, methoxycarbonylmethyl,methoxycarbonylethyl, methoxycarbonylpropyl, ethoxycarbonylmethyl,ethoxycarbonylethyl, ethoxycarbonylpropyl, propoxycarbonylethyl,hydroxymethyl, hydroxyethyl, hydroxypropyl or hydroxybutyl, and A isnitrogen or -C-R₅ wherein R₅ is acetyl, propionyl, methoxycarbonyl,ethoxycarbonyl, aminocarbonyl, methylaminocarbonylor.dimethylaminocarbonyl, and B is=NR₆ wherein R₆ is methyl, ethyl,propyl, isopropyl, butyl, 2-butyl or 1,1-dimethylethyl, or B is═CR₇ R₈wherein R₇ is H, methyl, ethyl, isopropyl, 3-pentyl, cyclopentyl orcyclohexyl and R₈ is hydrogen, cyano, carboxyl or methyl, ethyl,isopropyl, 3-pentyl, acetyl, propynyl, methoxycarbonyl, ethoxycarbonyl,aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl orhydrazinocarbonyl, or R₇ and R₈ together with the carbon atom to whichthey are attached form a spirocyclopropyl, spirocyclobutyl,spirocyclopentyl or spirocyclohexyl ring or R₇ and R₈ together form anisopropylidene or cyclohexylidine ring
 8. The method of claim 1 or 2comprising treating said conditions with a compound of formula I whereinR₁ is a phenyl of formula II wherein R₂, R₃, R₄ is hydrogen, hydroxychlorine C₁ -C₅ -alkyl, C₁ -C₅ -alkoxy, C₂ -C₅ -alkoxyloxy ortrifluoromethyl.
 9. The method of claim 1 comprising treating saidconditions with a compound of formula I wherein A is nitrogen and Bis═CR₇ R₈ wherein R₇ or R₈ are hydrogen C₁ -C₆ -alkyl or together form aC₃ -C₇ spirocycle.
 10. A method for the inhibition of erythrocyteaggregation which comprises treating patients having conditions withneed of such inhibition with an effective amount of at least onecompound selected from the group consisting of7,7-dimethyl-2-(2-thienyl)-6, 7-dihydro-3H, 5H -pyrrolo -benzimidazol-6-one7,7-dimethyl-2-(3,4-dichlorophenyl) -6,7-dihydro-3H,5H-pyrrolobenzimidazol-6-one, 7,7-dimethyl-2-(4-trifluoromethylphenyl)-6,7-dihydro-3H,5H-pyrrolo benzimidazol-6-one, ' -phenyl-spiro -6'-one,and 2'-(4-methoxyphenyl)-spiro -6'-oneor a physiologically acceptablesalt thereof in a pharmaceutically acceptable carrier.
 11. the method ofcalim 1, 2, 9 or 10 comprising treating said conditions with an amountof from 10 to 2,000 mg per day per body weight of 75 kg.